Objective The total saponins of Baibiandou (Lablab Semen Album) are prepared from the traditional Chinese medicine Lablab Semen Album through extraction, separation and purification steps. Although there are studies on the targeting and treatment of cancer with Xiaobiandou (Lens culinaris) lectin in nude mice with human liver cancer transplants, there is a lack of research on how the total saponins of Lablab Semen Album affect the growth of the prostate cancer cell line PC-3. Therefore, it is necessary to explore the mechanism through which total saponins of Lablab Semen Album impact the growth of the prostate cancer cell line PC-3.Methods In this paper, the CCK8 method was adopted to test the effect of different concentrations of Lablab Semen Album total saponins on the growth of PC-3 cells. Transcriptomics was used to analyze the molecular mechanism of the inhibition of the growth of PC-3 cells by Lablab Semen Album total sponins, and the related differential gene expression was verified by real-time quantitative PCR and Western blot experiments. Western blot and CCK8 assays were used to detect the survival rate of total saponins in Lablab Semen Album-treated PC-3 cells overexpressing ALDH7A1.Results With increasing concentration of Lablab Semen Album total saponins, the survival rate of PC-3 cells was reduced significantly, and the IC₅₀ value of Lablab Semen Album total saponins was 1 086 mg/L. The transcriptomics sequencing results showed that compared to the control group, there were 2 360 differentially expressed genes in the cells treated with Lablab Semen Album total saponins, of which 1 982 genes were upregulated and 378 genes were downregulated. The GO results showed that the differentially expressed genes were significantly enriched in biological processes closely related to cancer onset and development. In addition, the KEGG analysis results also showed that the differentially expressed genes were enriched in the signaling pathway of tumor metabolism. When the differential genes were further verified, the results showed that compared to the control group, the protein expression levels of ALDH7A1, GCAT and PGAM4 in the prostate cancer cells treated with Lablab Semen Album total saponins were obviously reduced (P<0.05), whereas the protein expression levels of DMGDH and CBSL were significantly increased (P<0.001). According to the results of in vitro cell experiments, the downregulated expression of ALDH7A1 in prostate cancer cells by total saponins of Lablab Semen Album inhibited their growth.Conclusion Lablab Semen Album total saponins may inhibit the growth of prostate cancer cells in vitro through the expression of ALDH7A1.